The most common cause of water problems in basements, or in below-grade family rooms and bedrooms as frequently built in the lower levels of bi-level type homes, is seepage from the outside which passes through cracks in the foundation walls and runs onto the floor. Attempting to seal such cracks, either from the inside or from the outside, is not only very costly but generally is also ineffective.
As a consequence, many other ways of solving the problem have been devised, but none of these have proved to be particularly practicable, usually because of the high cost and the difficulty of installation. In the U.S. Pat. to Munro, No. 2,163,286, for example, a strip of flexible material is embedded in the masonry during construction of the building wall, while the masonry is in a plastic state, and the strip is withdrawn when the masonry is partly set so as to leave an unobstructed channel opening to the exterior of the wall in the place originally occupied by the strip. This construction is not only costly and time consuming to fabricate but the openings tend to become plugged, thus reducing their effectiveness. Further, the system will not remove seepage which passes through the wall by way of cracks which subsequently develop.
Various types of flashing have been developed, such as disclosed in Blacher U.S. Pat. No. 2,122,926 and Doing U.S. Pat. No. 2,154,734, but, while these may be somewhat effective to prevent downward seepage through the cement or motor joints, they are not effective to prevent lateral seepage through the wall from outside or inside.
Healy et al U.S. Pat. No. 3,654,765 discloses a below-grade or subterranean wall drain positioned against the exterior wall of a building. The drain would not be effective to prevent seepage through cracks which might develop in the wall at a level above the top of the drain unit.
Murati U.S. Pat. No. 3,656,268 relates primarily to permeable wooden cofferdams for open excavations, intended to guide water which seeps therethrough to a drainage system. The arrangement utilizes a flexible, water-impermeable membrane to conduct water to vertical conduits which then conduct the water to a horizontal conduit. Murati could not possibly accomplish the objective attained by Applicant's device namely, preventing seepage through random cracks in a building wall from flowing onto a floor which is at a level below the level of the cracks.
Marchi U.S. Pat. No. 2,948,993 utilizes vertically positioned elongated sheets of plastic or Masonite, one face of which is in contact with a concrete floor. The sheets are held away from the walls by a plurality of spacers, thereby forming vertical drain passages leading downwardly directly into a bed of gravel. It will be noted, first, that no direct horizontal passages are provided to faciliate run-off of seepage under the floor and, second, the Marchi construction is expensive and time consuming to fabricate.
Gazzo U.S. Pat. No. 3,852,925 is intended primarily to control seepage through paneled walls formed of hollow blocks. Granular material such as gravel is piled against the wall and on top of a footing supporting the wall. Next, a generally "L" shaped piece of plastic is placed over and against the gravel and is taped to the paneling, after which the concrete floor is poured to hold the plastic in place. The Gazzo arrangement may be utilized only in conjunction with a paneled wall and appears to be impracticable because (a) there is no suggested way to support the gravel until the plastic is positioned and (b) there is no suggested way to support the plastic against the pressure exerted by the gravel until the concrete is poured.
While the foregoing prior art devices suggest various systems for controlling seepage, none suggest a simple, inexpensive; yet effective, commercially feasible, system for solving the problem.